Question 1

The process of taking a DNA template and making a complementary RNA molecule is called
A) transposition.
B) transertion.
C) replication.
D) translation.
E) transcription.

Accepted Answer

The process described in the question is transcription, which is the process of synthesizing an RNA molecule from a DNA template. Transposition involves the movement of genetic elements within a genome, transertion is not a recognized biological process, replication is the process of copying a DNA molecule, and translation is the process of synthesizing a protein from an RNA molecule.

Question 2

Molecules of sRNA do not encode proteins but are used to ________ the stability or translation of specific mRNAs into proteins.
A) start
B) regulate
C) stop
D) speed up
E) slow down

Accepted Answer

Molecules of sRNA are used to regulate the stability or translation of specific mRNAs into proteins. They do not encode proteins themselves. Therefore, the best choice is B) regulate.

Question 3

The average half-life for mRNA in a typical bacterium such as E. coli is
A) 1-3 seconds.
B) 10-30 seconds.
C) 1-3 minutes.
D) 1-3 hours.
E) 1-3 days.

Accepted Answer

The average half-life for mRNA in a typical bacterium such as E. coli is around 1-3 minutes. This means that after 1-3 minutes, half of the mRNA molecules will have degraded. This is much shorter than the half-life of mRNA in eukaryotic cells, which can range from hours to days.

Question 4

________ RNA polymerase plus sigma factor together are called ________.
A) Transcription; translation
B) Holoenzyme; core
C) Translation; transcription
D) Core; holoenzyme
E) Ribosome; rRNA

Accepted Answer

RNA polymerase requires a sigma factor to initiate transcription. The holoenzyme refers to the complete RNA polymerase complex consisting of the core enzyme plus the sigma factor. Thus, the answer is (D) Core; holoenzyme.

Question 5

The RpoD sigma-70 factor of E. coli recognizes promoters for
A) stress-response genes.
B) motility and chemotaxis genes.
C) "housekeeping" genes.
D) heat shock-induced genes.
E) genes for nitrogen metabolism.

Accepted Answer

The RpoD sigma-70 factor of E. coli recognizes promoters for "housekeeping" genes, which are involved in basic cellular functions such as metabolism, DNA replication, and cell division.

Question 6

Which of the following is normally read as a stop codon but encodes tryptophan in vertebrate mitochondria?
A) AUG
B) UCA
C) UAC
D) UGA
E) UAG

Accepted Answer

UGA is typically a stop codon in most organisms, but in vertebrate mitochondria, it can encode the amino acid tryptophan.

Question 7

Which of the following is NOT part of initiation of transcription?
A) -10 and -35 sequences
B) binding of RNA polymerase to the beginning of the gene
C) melting of the helix
D) binding of sigma factor to promoter followed by binding of core RNA polymerase
E) base pairing of the first nucleotide of the RNA

Accepted Answer

The answer of Which of the following is NOT part...

Question 8

The unusual bases found in tRNA are poor substrates for
A) proteases.
B) polymerases.
C) ribosomes.
D) ribozymes.
E) RNases.

Accepted Answer

The unusual bases found in tRNA are poor substrates for RNases, which are enzymes that degrade RNA. These modifications can protect tRNA from degradation, ensuring its stability and functionality in protein synthesis.

Question 9

Which drug intercalates into DNA and inhibits transcription in both prokaryotes and eukaryotes?
A) streptomycin
B) actinomycin D
C) chloramphenicol
D) rifampin
E) tetracycline

Accepted Answer

Actinomycin D is a drug that intercalates into the DNA helix and prevents transcription. It binds preferentially to GC-rich regions of DNA and inhibits both prokaryotic and eukaryotic RNA polymerase. Streptomycin inhibits protein synthesis by binding to the small subunit of prokaryotic ribosomes, chloramphenicol inhibits protein synthesis by binding to the 50S subunit of the bacterial ribosome, rifampin inhibits transcription by binding to bacterial RNA polymerase, and tetracycline inhibits protein synthesis by binding to the 30S subunit of the bacterial ribosome.

Question 10

A consensus sequence of any genetic element is
A) sequences that are rarely found in nature.
B) the sequence with the most likely base (or bases) at each position.
C) hairpins in RNA to slow down or stop transcription.
D) sequences to which ribosomes bind.
E) primer sequences used to initiate transcription.

Accepted Answer

A consensus sequence is the sequence that is the most likely base (or bases) at each position in a genetic element, based on the frequency of occurrence of each base at that position in similar genetic elements.

Question 11

The figure below shows subunits of a structure in a bacterial cell. This structure is 
A) a type I secretion system.
B) RNA polymerase.
C) a ribosome.
D) aminoacyl-tRNA synthetase.
E) sigma factor and RNA polymerase.

Accepted Answer

The subunits shown in the figure resemble the structure of a ribosome, which is responsible for protein synthesis in bacterial cells.

Question 12

Most tRNA molecules begin with a 5' ________ and all end with a 3' ________, to which the amino acids attach.
A) phosphate; hydroxyl
B) C; GGA
C) G; CCA
D) A; TTA
E) C; AAT

Accepted Answer

Most tRNA molecules start with a 5' guanine (G) and all end with a 3' cytosine-cytosine-adenine (CCA) sequence, where the amino acids attach.

Question 13

A researcher is studying transcription and has added a chemical to a transcription experiment using both E. coli and mammalian cells. This chemical inhibits both systems. The chemical is most likely
A) streptomycin.
B) rifamycin.
C) erythromycin.
D) rifampin.
E) actinomycin D.

Accepted Answer

Actinomycin D is a well-known inhibitor of transcription that can affect both prokaryotic and eukaryotic systems. Therefore, it is the most likely chemical to inhibit both E. coli and mammalian cell transcription in the experiment described. Streptomycin and erythromycin are antibiotics that affect translation, while rifampin and rifamycin are antibiotics that target bacterial RNA polymerase, and therefore would not be effective in mammalian cells.

Question 14

In the figure below, which label represents the promoter? 
A) A
B) B
C) C
D) D
E) -35

Accepted Answer

The promoter is the DNA sequence to which RNA polymerase binds in order to initiate transcription. In prokaryotes, the promoter typically includes two regions: the -10 box (also known as the Pribnow box), which is centered around 10 bases upstream of the transcription start site, and the -35 box, which is centered around 35 bases upstream. In this figure, label A represents the -10 box, which is part of the promoter.

Question 15

In the absence of Rho, what can bring about transcription termination?
A) stem and loop and stretches of uridines
B) stem and loop only
C) GC-rich region near the 3¢ terminus
D) GC-rich region near the 3¢ terminus followed by four to eight uridines
E) stem and loop followed by a GC-rich region

Accepted Answer

The answer of In the absence of Rho, what can...

Question 16

In the figure below, which label represents the Shine Delgarno site? 
A) A
B) B
C) C
D) D
E) -35

Accepted Answer

The Shine Delgarno site is a sequence on mRNA that is complementary to a sequence on the 16S rRNA of the small ribosomal subunit in bacteria. It helps in the recognition of the start codon and the correct positioning of the ribosome during translation. In this figure, label B represents the Shine Delgarno site, as it is the sequence that is upstream and complementary to the 16S rRNA. Labels A, C, and D are not related to the Shine Delgarno site, and -35 is a region on the promoter that is recognized by RNA polymerase for transcription initiation.

Question 17

Using the genetic code shown below, find the correct start and stop codons. Which of the following peptides might this message code for? 
5'-GAGUUAUGCACGGGUUCUAUGUGUAG-3'
A) GLU-LEU-CYS-MET-GLY-SER-MET-CYS
B) MET-GLY-SER-MET-CYS
C) MET-HIS-GLY-PHE-TYR-VAL
D) MET-CYS-ILE-LEU-GLY-THR-TYR
E) ASP-VAL-TYR-LEU-GLY-TYR-VAL-LEU

Accepted Answer

The answer of Using the genetic code shown below, find...

Question 18

DNA-dependent ________ polymerase makes a copy of DNA that is then used for translation. The process carried out by this enzyme is called ________.
A) RNA; transformation
B) protein; transcription
C) DNA; transcription
D) RNA; transcription
E) protein; transposition

Accepted Answer

DNA-dependent RNA polymerase makes a copy of DNA into RNA, a process known as transcription, which is then used for translation into proteins.

Question 19

During transcription of the ________ genes, normal, unmodified bases are incorporated, but specific enzymes modify some of these later.
A) tRNA
B) tmRNA
C) mRNA
D) sRNA
E) catalytic RNA

Accepted Answer

tRNA genes undergo post-transcriptional modifications where specific enzymes modify certain bases after the initial transcription process.

Question 20

Which of the following is NOT true of initiation of transcription?
A) The RNA polymerase holoenzyme binds.
B) GTP hydrolysis catalyzes bubble formation.
C) The promoter unwinds.
D) The first rNTP is usually a purine.
E) Position +1 marks the start of the gene.

Accepted Answer

NTP hydrolysis, not GTP hydrolysis, catalyzes the formation of the transcription bubble.

Quiz 8: Transcription, Translation, and Bioinformatics

The process of taking a DNA template and making a complementary RNA molecule is called

Molecules of sRNA do not encode proteins but are used to ________ the stability or translation of specific mRNAs into proteins.

The average half-life for mRNA in a typical bacterium such as E. coli is

RNA polymerase plus sigma factor together are called .

The RpoD sigma-70 factor of E. coli recognizes promoters for

Which of the following is normally read as a stop codon but encodes tryptophan in vertebrate mitochondria?

Which of the following is NOT part of initiation of transcription?

The unusual bases found in tRNA are poor substrates for

Which drug intercalates into DNA and inhibits transcription in both prokaryotes and eukaryotes?

A consensus sequence of any genetic element is

The figure below shows subunits of a structure in a bacterial cell. This structure is

Most tRNA molecules begin with a 5' and all end with a 3' , to which the amino acids attach.

A researcher is studying transcription and has added a chemical to a transcription experiment using both E. coli and mammalian cells. This chemical inhibits both systems. The chemical is most likely

In the figure below, which label represents the promoter?

In the absence of Rho, what can bring about transcription termination?

In the figure below, which label represents the Shine Delgarno site?

Using the genetic code shown below, find the correct start and stop codons. Which of the following peptides might this message code for? 5'-GAGUUAUGCACGGGUUCUAUGUGUAG-3'

DNA-dependent polymerase makes a copy of DNA that is then used for translation. The process carried out by this enzyme is called .

During transcription of the ________ genes, normal, unmodified bases are incorporated, but specific enzymes modify some of these later.

Which of the following is NOT true of initiation of transcription?